Field of the Invention
The present invention relates to a three-dimensional object formation powder material, a three-dimensional object formation material set, and a three-dimensional object formation method.
Description of the Related Art
Conventionally, metal moldings have been produced using molds. The techniques for producing metal moldings using molds have problems that molds are generally expensive, and are not necessarily suitable for production of complex fine moldings or for small-lot production. Recently, there has been a rise in the needs for small-lot production of complex fine three-dimensional objects. A powder sintering method, a powder bonding method, etc. have been proposed as techniques for answering the needs (see, e.g., Japanese Patent Application Laid-Open (JP-A) Nos. 2000-328106, 2006-200030, and 2003-48253).
The powder sintering method is a method of obtaining a desired three-dimensional object by irradiating a thin layer with laser light to form a thin sintered body, and repeating this process to stack up thin sintered bodies sequentially over the thin sintered body. The powder bonding method is a method of obtaining a desired three-dimensional object by using an adhesive agent instead of performing sintering in the powder sintering method.
However, the powder sintering method has problems that it is necessary to stack one layer and each time check and correct whether the layer is misfitted or not, and that the shape may collapse during the production because the strength of the stacked-up object is not sufficient. The powder bonding method cannot fill a void that may be left opened during stacking of powder layers because the powder cannot melt unlike by laser, and may produce a sintered body containing many voids without being able to improve the density.
When a squeegee is used to stack up layers of particles, voids are left opened and reduce the points of contact for sintering, which weakens the strength of a green body (a hardened product to be sintered) and a sintered body. Generally, reduction of particle diameter improves the density of a sintered body, which however is problematic because it is difficult to compactly pack small-diameter particles uniformly and densely with a coater.